The reactants are favored - shift to the left. The reverse reaction is favored - shift to the left. The forward reaction is favored - FAVORS PRODUCTS. Adding water vapor will cause the direction of equilibrium to shift to the right
Work Step by Step
Notice the REVERSE reaction produces HEAT. If the temperature is lowered (less heat), the reverse reaction will be favored to minimize stress. To relieve the stress caused by an increase in temperature, you would REDUCE the number of GAS molecules. The reactants have less number of gas molecules. Because hydrogen gas is removed, the reaction will favor the FORWARD reaction so hydrogen gas is produced to make up for the lost hydrogen. Adding water vapor will cause the direction of equilibrium to shift to the right (away from the direction of water vapor being produced) to relive the stress.